Purpose:Best vitelliform macular dystrophy (BVMD) is an autosomal dominant macular degeneration. Lesions of varying size and appearance are visible on fundus exam, however it is not known how these affect the overlying photoreceptor mosaic. Here we used high-resolution retinal imaging tools to characterize photoreceptor structure in a family with individuals at various stages of BVMD.

Methods:Four patients from a family with BVMD were found to harbor a previously described heterozygous mutation in the BEST1 gene (p.Arg218Cys). Fundus examination revealed atrophic changes in the macula (stage 4a) in a 50 year-old female. Her 59 year-old sister had fibrotic changes in the macula (stage 4b). Her 16 year-old son had RPE changes in the central macula (stage 1), while her 18 year-old daughter had a homogeneous vitelliform lesion (stage 2). The integrity of the inner segment/outer segment (IS/OS) junction was assessed using spectral domain optical coherence tomography (SD-OCT), and the photoreceptor mosaic was imaged using an adaptive optics scanning laser ophthalmoscope (AOSLO).

Results:In the patient with Stage 4a Best disease, SD-OCT showed multiple lesions in the macula disrupting the IS/OS junction. Images of the photoreceptor mosaic showed severe photoreceptor degeneration within the lesions and a well conserved cone mosaic in some but not all areas between lesions. In the patient with stage 4b Best disease, SD-OCT revealed a lamellar hole and a severely disrupted IS/OS junction. Using the AOSLO, we observed diffuse photoreceptor disruption, though there were patches of retained photoreceptors within the central retina. In the patient with stage 1 Best disease, SD-OCT revealed grossly normal retinal lamination, though the outer hyperreflective band corresponding to the cone OS tips showed diffuse scattering. Images of the photoreceptor mosaic showed disrupted photoreceptor waveguiding in areas corresponding to the RPE changes, with normal cone density immediately surrounding the RPE changes. In the patient with stage 2 Best disease, SD-OCT showed a vitelliform lesion between the RPE and OS tips, with a mottled IS/OS overlying the lesion. A coarse photoreceptor mosaic was observed within the vitelliform lesion, with a normally-appearing mosaic adjacent to the lesion.

Conclusions:Our data show that photoreceptor disruption varies at different stages of BVMD. In particular, AOSLO imaging confirmed areas of normal photoreceptors remain within all types of BVMD lesions studied here, and no significant photoreceptor changes were observed in areas adjacent to active lesions.